Eternal Hunt vs Moth Green

How close are they?

ΔE 21.0, loose: different enough that you should pick on purpose. Moth Green is noticeably lighter, more saturated, warmer than Eternal Hunt.

Can I use Moth Green instead of Eternal Hunt?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Moth Green is noticeably lighter, more saturated, warmer than Eternal Hunt.

Can I use Eternal Hunt instead of Moth Green?

The same difference applies the other way round: Eternal Hunt is noticeably darker, more muted, cooler.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.